Single slot loader slot bearing

ABSTRACT

A loader slot bearing includes a housing and a truncated ball. The housing has an interior area that is defined by an inner bearing surface which has a concave contour defining a circumference. A single slot extends axially partway into the inner bearing surface and has a slot arc section area extending axially inward. The slot arc section area has a first circumferential slot-end, a second circumferential slot-end, and a slot arc length measured between the first circumferential slot-end and the second circumferential slot-end. A ratio of the slot arc length to the circumference of the interior area is about 0.20 to 0.35. The truncated ball has a convex exterior surface. The truncated ball is positioned in the slot and rotated so that the truncated ball is rotatably retained by the inner bearing surface. The truncated ball is angularly misalignable relative to the annular housing.

CROSS REFERENCE TO RELATED APPLICATION

This application is a non-provisional application of and claims priorityto commonly owned U.S. Provisional Patent Application No. 63/152,619,filed on Feb. 23, 2021, the contents of which is incorporated herein byreference in its entirety.

TECHNICAL FIELD

The present disclosure relates generally to a rod end having a loaderslot spherical bearing therein. More particularly, the presentdisclosure relates to an injection molded loader slot spherical bearinghaving a single slot therein for a rod end. The slot is aligned with,and extends toward, the shaft of the rod end.

BACKGROUND

Rod ends having loader slot bearings therein typically have a rod endhead, a rod end shank (or shaft), and a rod end bore in the rod endhead. Typical loader slot bearings have two slots in the bore at thethree o'clock and nine o'clock positions of the rod end head, with therod end shank at the six o'clock position. In typical injection moldedloader slot designs, the race material is molded into the slots afterthe ball is aligned in place such that there is no metal retaining theball in the area of the slots when the ball is axially loaded toward theslots. However, when the ball is axially loaded toward the slots, theplastic molded material of the slots reduces the load capacity. Intypical two slot loader slot bearing designs, the slots account forabout two hundred degrees of the area surrounding the ball. Thus, morethan half of the ball loses metal retainment, which reduces axial loadcapacity. Also, when the ball is axially loaded toward the non-slottedareas, about half of the ball is in contact with metal and the otherhalf is in contact with plastic. The metal-to-metal contact helps retainthe ball during axial loads and keeps the rod end stiff during radial(tension) loads. While this metal-to-metal contact is good for staticload capacity, it increases the wear on the bearing.

Thus, there is a need for an improved loader slot bearing that overcomesthe foregoing problems.

SUMMARY

According to aspects illustrated herein, there is provided a loader slotbearing including an annular housing and a truncated ball. The annularhousing has a first axial housing-surface, a second axialhousing-surface, and an interior area extending between the first axialhousing-surface and the second axial housing-surface. The interior areais defined by an inner bearing surface that extends between the firstaxial housing-surface and the second axial housing-surface. The innerbearing surface has a concave contour (e.g., elliptical, arcuate, orspherical) defining a circumference measured proximate to the firstaxial housing-surface. A single slot extends axially partway into theinner bearing surface from the first axial housing-surface. The slot hasa slot arc section area extending axially inward from the first axialhousing-surface. The slot arc section area has a first circumferentialslot-end, a second circumferential slot-end, and a slot arc lengthmeasured between the first circumferential slot-end and the secondcircumferential slot-end. A ratio of the slot arc length to thecircumference of the interior area is about 0.20 to about 0.35. Thetruncated ball has a convex spherical exterior surface extending betweena first axial ball-surface and a second axial ball-surface. Thetruncated ball is positioned in the slot and rotated so that thetruncated ball is rotatably retained by the inner bearing surface. Thetruncated ball is angularly misalignable relative to the annularhousing.

In one embodiment, the slot has a first lateral width measured betweenthe first circumferential slot-end and the second circumferentialslot-end, and the truncated ball has a first axial width measuredbetween the first axial ball-surface and the second axial ball-surface.The first axial width is less than the first lateral width.

In one embodiment, the slot arc section area has a first radius, and thespherical exterior surface has a first outer diameter. The first radiusis greater than the first outer diameter divided by 2.

In one embodiment, the inner bearing surface has a first center ofcurvature, and the slot arc section area has a second center ofcurvature. The second center of curvature is positioned a distance fromthe first center of curvature.

In one embodiment, the annular housing has a second axial width measuredbetween the first axial housing-surface and the second axialhousing-surface, and the slot has a first axial depth extending from thefirst axial housing-surface toward the second axial housing-surface. Aratio of the first axial depth to the second axial width is about 0.40to about 0.60.

In one embodiment, the inner bearing surface includes a radial groovecentrally located axially between the first axial housing-surface andthe second axial housing-surface and extending circumferentially aroundthe interior area.

In one embodiment, the slot includes a notch extending radially outwardinto the annular housing. The notch has a first radial depth.

In one embodiment, an insert is positioned in the slot. The insert hasan insert arc section area that conforms in shape to the slot arcsection area.

In one embodiment, the truncated ball has a cylindrical bore extendingbetween the first axial ball-surface and the second axial ball-surface.The bore is defined by an interior ball-surface.

In one embodiment, the truncated ball is dropped into the interior areaof the annular housing.

In one embodiment, a liner is molded between the truncated ball and theannular housing.

In one embodiment, the liner is molded over an insert that is positionedin the slot.

In one embodiment, the liner is formed of an injection-moldablematerial.

In one embodiment, an insert is positioned in the slot and a liner ismolded between the truncated ball and the annular housing. The liner hasa first hardness and the insert has a second hardness that is greaterthan the first hardness.

In one embodiment, the slot extends circumferentially from the firstcircumferential slot-end to the second circumferential slot-end. Theinner bearing surface extends continuously circumferentially a bearingsurface arc length outside of the slot from the first circumferentialslot-end to the second circumferential slot-end.

In one embodiment, the bearing surface arc length is defined by a ratioof the bearing surface arc length to the circumference of the interiorarea about 0.65 to about 0.80, to provide support for the truncatedball.

In some embodiments, the concave contour is elliptical.

According to aspects illustrated herein, there is provided a rod endincluding a loader slot bearing and a shaft. The loader slot bearingincludes an annular housing and a truncated ball. The annular housinghas a first axial housing-surface, a second axial housing-surface, andan interior area extending between the first axial housing-surface andthe second axial housing-surface. The interior area is defined by aninner bearing surface that extends between the first axialhousing-surface and the second axial housing-surface. The inner bearingsurface has a concave contour (e.g., elliptical, arcuate, or spherical)defining a circumference measured proximate to the first axialhousing-surface. A single slot extends axially partway into the innerbearing surface from the first axial housing-surface. The slot has aslot arc section area extending axially inward from the first axialhousing-surface. The slot arc section area has a first circumferentialslot-end, a second circumferential slot-end, and a slot arc lengthmeasured between the first circumferential slot-end and the secondcircumferential slot-end. A ratio of the slot arc length to thecircumference of the interior area is about 0.20 to about 0.35. Thetruncated ball has a convex spherical exterior surface extending betweena first axial ball-surface and a second axial ball-surface. Thetruncated ball is positioned in the slot and rotated so that thetruncated ball is rotatably retained by the inner bearing surface. Thetruncated ball is angularly misalignable relative to the annularhousing. The shaft has a longitudinal axis and extends from and isintegral with the annular housing. The slot is centrally located alongthe longitudinal axis.

In one embodiment, the slot is located adjacent to the shaft.

In one embodiment, the inner bearing surface has a first center ofcurvature, and the slot arc section area has a second center ofcurvature. The second center of curvature is positioned a distance fromthe first center of curvature. The second center of curvature is locatedcloser to the shaft than the first center of curvature.

In one embodiment, an insert is positioned in the slot and a liner ismolded between the truncated ball and the annular housing. The liner hasa first hardness and the insert has a second hardness that is greaterthan the first hardness.

In some embodiments, the concave contour is elliptical.

Any of the foregoing embodiments may be combined.

BRIEF DESCRIPTION OF THE DRAWING

Referring now to the Figures, which are exemplary embodiments, andwherein the like elements are numbered alike:

FIG. 1 is a side view of a rod end with a loader slot spherical bearingtherein according to an embodiment of the present invention.

FIG. 2 is a cross sectional view of the rod end and loader slot bearingof FIG. 1, taken across section 2-2 of FIG. 1.

FIG. 3 is an enlarged view of a portion of the rod end of FIG. 1 shownwithout the truncated ball.

FIG. 4 is an enlarged view of a portion of the rod end of FIG. 1 shownwithout the truncated ball.

FIG. 5 is a cross sectional view of the loader slot bearing of FIG. 2shown without the truncated ball.

FIG. 6 is a cross sectional view of a loader slot bearing having a notchin the slot of the annular housing according to an embodiment of thepresent invention.

FIG. 7 is a perspective view of a rod end having an insert positioned inthe slot of the annular housing according to an embodiment of thepresent invention, but with no liner or truncated ball shown for clarityof illustration.

FIG. 8 is a cross sectional view of the rod end of FIG. 7 shown with theliner, insert, and truncated ball.

FIG. 9 is a cross sectional view of a cartridge embodiment of the loaderslot bearing of the present invention.

FIG. 10 is a front view of the loader slot bearing of FIG. 9.

DETAILED DESCRIPTION

As shown in FIG. 1, a rod end is generally designated by the number 10.The rod end 10 includes a loader slot bearing 20 having an annularhousing 22. A shaft 50 extends from and is integral with the annularhousing 22 and thereby forms the rod end 10. The shaft 50 has a threadedarea 52 (e.g., male threads) for threading the rod end 10 into a femalethread 72 of a support frame 70. While the shaft 50 is shown secured tothe support frame 70 via the threaded area 52 and the female threads 72,the present invention is not limited in this regard as the shaft 50 maybe integral with the support frame 70 or secured to the support frame 70with one or more alternative fasteners such as a shaft with femalethreads threaded on to a male threaded pin extending from the supportframe 70, a flanged connection, or welded to the support frame 70.

While the loader slot bearing 20 is shown and described with referenceto FIG. 1 as being integral with the shaft 50, the present invention isnot limited in this regard as the shaft 50 may be eliminated resultingin a cartridge type loader slot bearing 200 as shown and described withreference to FIGS. 9 and 10. The loader slot bearing 200 is similar tothe loader slot bearing 20 and employs similar reference numeralscorresponding to the respective elements thereof and illustrates acylindrical outside surface 22E of the annular housing 22 of the slotloader bearing 200. Therefore, the following description applies to boththe slot loader bearing 20 and the slot loader bearing 200, asappropriate.

The annular housing 22 and the shaft 50 are manufactured from a metallicmaterial, such as, a stainless steel (e.g., an austenitic, martensiticor precipitation hardened stainless steel), a bearing steel (e.g., ASTM52100), a carbon steel (e.g., C1018), an alloy steel (e.g., 4130),aluminum (e.g., 6061), Inconel or a titanium based alloy. In someembodiments, the annular housing 22 and the shaft 50 are manufacturedfrom a polymer based material, such as, nylon, acetal,polyetheretherketone, acrylonitrile butadiene styrene,polytetrafluoroethylene, and thermoplastic elastomer, with or withoutadditives such as glass filler, fibers, lubricants, oil, greases,graphite, or any other known filler materials.

As shown in FIG. 2, the annular housing 22 has a first axialhousing-surface 22A, a second axial housing-surface 22B and an interiorarea 24 extending between the first axial housing-surface 22A and thesecond axial housing-surface 22B. The annular housing 22 has an axialwidth W3 as measured between the first axial housing-surface 22A and thesecond axial housing-surface 22B. In one embodiment, each of the firstaxial housing-surface 22A and the second axial housing-surface 22B havea chamfer 22C formed on a radially innermost portion thereof. Theinterior area 24 is defined by an inner bearing surface 26 that extendsbetween the first axial housing-surface 22A and the second axialhousing-surface 22B. As shown in FIGS. 3-4, the inner bearing surface 26has a concave contour that defines a radially inward facing surface areaand a circumference of the interior area 24 measured proximate to thefirst axial housing-surface 22A. In some embodiments, the inner bearingsurface 26 has a concave elliptical contour. In some embodiments, theinner bearing surface 26 has a concave spherical contour. The radiallyinward facing surface area of the inner bearing surface 26 is continuousand uninterrupted with the exception of a single slot 30, as describedfurther herein. The inner bearing surface 26 has a first center ofcurvature C1 that is located at the intersection of an axially extendingcentral axis A of the interior area 24 and a radially extendinglongitudinal axis L. As shown in FIG. 5, the inner bearing surface 28has an effective axial width W4 that extends between respective axialinward portions of the chamfers 22C of the first axial housing-surface22A and the second axial housing-surface 22B. The annular housing 22 hasan opening proximate to each of the first axial housing-surface 22A andthe second axial housing-surface 22B at the minimum inside diameter atthe peak of the chamfer 22C which each have an inside diameter D10 asshown for example in FIG. 3. In some embodiments, the inner bearingsurface 26 has a radial groove 27 formed therein, as illustrated inFIGS. 2, 5, 6, 7, and 8. The radial groove 27 is centrally locatedaxially between the first axial housing-surface 22A and the second axialhousing-surface 22B as measured along the width W3, and the radialgroove 27 extends circumferentially around the interior area 24. Theradial groove 27 provides additional axial retention of a liner 80molded between a truncated ball 40 and the annular housing 22. The slot30 provides additional rotational retention of the liner 80 moldedbetween the truncated ball 40 and the annular housing 22. In theembodiment with the radial groove 27, the radially inward facing surfacearea of the inner bearing surface 26 is continuous and uninterruptedwith the exception of the slot 30 and the radial groove 27. While theradial groove 27 is shown and described as being centrally locatedaxially between the first axial housing-surface 22A and the second axialhousing-surface 22B, the present invention is not limited in this regardother configurations are contemplated including but not limited to theradial groove 27 being asymmetrically located between the first axialhousing-surface 22A and the second axial housing-surface 22B and theaxial groove being circumferentially non-continuous and configured intwo or more segments.

As best shown in FIGS. 3-5, the slot 30 extends partially and axially(i.e., parallel to the central axis A) into the inner bearing surface 26from the first axial housing-surface 22A. As shown in FIG. 4, the slot30 has a lateral width W1 extending perpendicular to a longitudinal axisL of the rod end 10 and parallel to the first axial housing-surface 22A.In some embodiments, the slot 30 is centrally located laterally alongthe longitudinal axis L (i.e. the longitudinal axis L bisects the slot30 as measured along the lateral width W1). As shown in FIG. 5, the slot30 extends an axial depth D3 that extends axially inward from the firstaxial housing-surface 22A towards and terminating prior to the secondaxial housing-surface 22B. A ratio of the axial depth D3 of the slot 30to the axial width W3 of the inner bearing surface 26 is about 0.40 toabout 0.60. As shown in FIGS. 3-4, the slot 30 defines a radially inwardfacing slot arc section area 32. The slot arc section area 32 has afirst circumferential slot-end 32A and a second circumferential slot-end32B defining a slot arc length A1 measured between the firstcircumferential slot-end 32A and the second circumferential slot-end32B. As shown in FIGS. 4 and 5, the slot arc section area 32 has a firstradius of curvature R1 measured from a second center of curvature C2located on a line parallel to and offset from the central axis A to theradially outermost surface of the slot 30, as described further herein.As shown in FIG. 3, the slot arc length A1 extends a circumferentialdistance along the circumference of the interior area 24 (i.e., theradially innermost portion of the slot 30). The circumferential distanceof the slot arc length A1 is defined by an angle θ as measured betweenthe radially inner most portion of the first circumferential slot-end32A and the radially inner most portion of the second circumferentialslot-end 32B. The angle θ is swung from the central axis A. In someembodiments, the angle θ is between about 75 degrees to about 120degrees, and preferably about 98 degrees, of the circumference of theinterior area 24. A ratio of the slot arc length A1 to the circumferenceof the interior area 24 measured at the first axial housing-surface 22Ais about 0.20 to about 0.35, and preferably about 0.27. As shown inFIGS. 4 and 5, the second center of curvature C2 and the line parallelto and offset from the central axis A is offset from the central axis Aby a radial distance D2, the radial distance D2 extending from thecentral axis A to a central offset axis A′, as best shown in FIG. 5. Insome embodiments, the distance D2 is not to exceed 0.030 inches. In someembodiments of the rod end 10, the slot 30 is located adjacent to theshaft 50. In some embodiments, the inner bearing surface 26 has thefirst center of curvature C1, and the slot arc section area Al has theradius of curvature R1 measured from the second center of curvature C2.The second center of curvature C2 is positioned a distance D2 from thefirst center of curvature Cl as best shown in FIG. 5 and for the rod 10embodiments, the second center of curvature C2 is located closer to theshaft 50 than the first center of curvature C1. It has been surprisinglydiscovered that the benefit of having the second center of curvature C2below (i.e., radially outward from) the first center of curvature C1 isthat this configuration facilitates assembly because the sphericalexterior surface 42 of the truncated ball 40 (see FIG.2) has a firstouter diameter D1 that is as close as possible in magnitude to the firstinner diameter D5 of the interior area 24 of the annular housing 22.Thus, in the configuration where the second center of curvature C2 isbelow the first center of curvature C1, there is extra space for thetruncated ball 40 to be placed within the housing 22.

As shown in FIG. 3, the slot arc length A1 of the slot 30 extendscircumferentially from a first circumferential slot-end 32A to a secondcircumferential slot-end 32B and the inner bearing surface 26 extendscontinuously circumferentially a bearing surface arc length A2 outsideof the slot 30 (e.g., proximate the first axial housing-surface 22A)from the first circumferential slot-end 32A to a second circumferentialslot-end 32B spanning an angle θ2 as measured between the firstcircumferential slot-end 32A and the second circumferential slot-end 32Bfrom the first center of curvature C1 (e.g., measured at the first axialhousing-surface 22A). In some embodiments, the angle θ2 is between about240 degrees to about 285 degrees, and preferably about 262 degrees, ofthe circumference of the interior area 24 measured at the first axialhousing-surface 22A. The bearing surface arc length A2 is defined by aratio of the bearing surface arc length A2 to the circumference of theinterior area, the measured at the first axial housing-surface 22A,about 0.65 to about 0.80, to provide support for the truncated ball.

As shown in FIG. 6, in some embodiments, the slot 30 has a notch 34 thatextends radially outward from the inner bearing surface 26 and extendscircumferentially only in the slot 30 along the slot arc section area32. The slot arc section area 32 has a first axial section slot-area 32Cproximate the first axial housing-surface 22A, and a second axialsection slot-area 32D extending axially inward from the first axialsection slot-area 32C. The notch 34 is formed in the second axialsection slot-area 32D and extends radially outward a radial depth D4 asmeasured parallel to the longitudinal axis L. The notch 34 extendsaxially partway in the slot 30 an axial width W5 which is less that theaxial depth D3 of the slot. In some embodiments, the radial depth D4 isbetween about 0.040 inches to about 0.100 inches. The notch 34 isconfigured to further improve retention of a molded liner 80 or insert60, as discussed below, when the loader slot bearing 20 is axiallyloaded.

While the loader slot bearing 20 is shown in FIGS. 1-6 and described ashaving a slot 30 that has particular dimensions, shape, and orientationin the annular housing 22, the present invention is not limited in thisregard and includes other configurations including but not limited tothe slot 30 being arranged in different positions along the first axialhousing-surface 22A, and the slot arc section area 32 having a smalleror a larger slot arc length A1.

In some embodiments, as shown for example in FIGS. 7-8, the slot 30 isconfigured to receive an insert 60. The insert 60 is preferably formedof a material that is harder than the molded liner 80. For example, insome embodiments, the insert 60 is formed of a metallic material, suchas, brass, stainless steel (e.g., an austenitic, martensitic orprecipitation hardened stainless steel), bearing steel (e.g., ASTM52100), carbon steel (e.g., C1018), alloy steel (e.g., 4130), aluminum(e.g., 6061), Inconel or a titanium based alloy, or a hard plasticmaterial, such as, nylon, acetal, polyetheretherketone, acrylonitrilebutadiene styrene, polytetrafluoroethylene, and thermoplastic elastomer,with or without additives such as glass filler, fibers, lubricants, oil,greases, graphite, or any other known filler materials. The insert 60has an insert arc section area 62 that conforms in shape to the slot arcsection area 32. In some embodiments, the insert 60 has a tab (notshown) that is complementary in shape to the notch 34 of the slot 30such that the tab is snap fit and retained in the notch 34 to secure theinsert 60 in the slot 30. The insert 60 is configured to snap fit intothe slot 30 to further improve both the axial and radial structuralsupport of the loader slot bearing 20. In some embodiments, the insert60 is positioned in the slot 30 (e.g., between the truncated ball 40 andthe annular housing 22), the insert has an insert arc section area 62that conforms in shape to the slot arc section area 32 and a liner 80molded between the truncated ball and the annular housing; and the liner80 is molded over the insert 60.

As shown in FIGS. 1-2, the loader slot bearing 20 includes a truncatedball 40 installed therein. As shown in FIG. 2, the truncated ball 40that has a convex spherical exterior surface 42 that has an axial widthW2 extending axially (i.e., parallel to the central axis A) between afirst axial ball-surface 42A and a second axial ball-surface 42B. Theaxial width W2 of the spherical exterior surface 42 is less than thelateral width W1 of the slot 30 so that the truncated ball 40 isinitially slid into the slot 30 and positioned in the slot 30 so thatthe first axial ball-surface 42A and the second axial ball-surface 42Band the first axial housing-surface 22A and the second axialhousing-surface 22B are parallel to one another. In some embodiments,the lateral width W1 is greater than the axial width W2 by no more than0.020 inches. The truncated ball 40 is rotated so that the truncatedball 40 is retained by the inner bearing surface 26. The truncated ball40 is angularly misalignable relative to the annular housing 22. Thespherical exterior surface 42 has a first outer diameter D1 that isgreater than the inside diameter D10 of the opening proximate to each ofthe first axial housing-surface 22A. The first radius R1 of the secondarc section 32 of the slot 30 is greater than the first outer diameterD1 divided by 2. In some embodiments, the first radius R1 is greaterthan the first outer diameter D1 divided by 2 by no more than 0.040inches. The first outer diameter D1 is less than or equal to a firstinner diameter D5 of the interior area 24 of the annular housing 22,such that there is a clearance CC of 0.000 inches to 0.050 inches,preferably 0.010 to 0.050 inches between the spherical exterior surface42 and the inner bearing surface 26 when the truncated ball 40 isinstalled and centered in the annular housing 22. In embodiments wherethe inner bearing surface 26 has a concave elliptical contour, the firstouter diameter D1 is less than or equal to a first inner diameter D5 ofthe interior area 24 of the annular housing 22 at least one point, suchthat there is a clearance CC of 0.000 inches to 0.050 inches, preferably0.010 to 0.050 inches between the spherical exterior surface 42 and theinner bearing surface 26 when the truncated ball 40 is installed andcentered in the annular housing 22. The truncated ball 40 has acylindrical bore 44 extending between the first axial ball-surface 42Aand the second axial ball-surface 42B. The bore 44 is defined by aninner ball-surface 46.

As shown in FIGS. 2 and 9, the loader slot bearing 20 is configured sothe truncated ball 40 can be dropped into the slot 30 so that a portionof the spherical exterior surface 42 (i.e., a portion extendingcontinuously between the first axial ball-surface 42A and the secondaxial ball-surface 42B) is in engagement with a corresponding portion ofthe inner bearing surface 26. This so-called drop in configuration isenabled by the slot 30 extending axially into the annular housing 22such that the axial depth D3 extends farther than a centerline CL (whichis coaxial with the longitudinal axis L) of the truncated ball 40 by anaxial depth differential G1. In some embodiments, the depth differentialG1 is about 0.0050 inches or greater. A manufacturing option isproducing the entry slot via conventional end milling that broaches theentry slot configuration completely or partially through one or more ofthe rod end faces, producing an entry slot that permits ballinstallation and removal on either side.

After the truncated ball 40 is positioned within the annular housing 22,a thermoplastic or thermosetting material is injection molded betweenthe truncated ball 40 and the annular housing 22 to form a liner 80, asshown in FIGS. 1, 2, and 8. The liner 80 fills in the slot 30 (includingthe notch 34) and the clearance between the spherical exterior surface42 and the inner bearing surface 26 to serve as a wear-resistancematerial that also provides further support and retention of the loaderslot bearing 20. As a result of the injection molding, the liner 80 isfixedly adhered to the inner bearing surface 26 and is in slidingengagement with the convex spherical exterior surface 42 of thetruncated ball 40. In some embodiments, as shown in FIG. 8, the insert60 is installed in the slot 30, as discussed above, and the liner 80 ismolded over the insert 60 and the inner bearing surface 26. In someembodiments, the liner 80 is formed of a plastic injection-moldablematerial including but not limited to nylon, acetal,polyetheretherketone, acrylonitrile butadiene styrene,polytetrafluoroethylene, and thermoplastic elastomer, with or withoutadditives such as glass filler, fibers, lubricants, oil, greases,graphite, or any other known filler materials. In some embodiments, theliner 80 is formed of an injection-moldable material including but notlimited to resins, polymers, graphite, composites, sintered powderedmetals, ceramic composite, and curing structural foams.

While the present disclosure has been described with reference tovarious exemplary embodiments, it will be understood by those skilled inthe art that various changes may be made and equivalents may besubstituted for elements thereof without departing from the scope of theinvention. In addition, many modifications may be made to adapt aparticular situation or material to the teachings of the inventionwithout departing from the essential scope thereof. Therefore, it isintended that the invention not be limited to the particular embodimentdisclosed as the best mode contemplated for carrying out this invention,but that the invention will include all embodiments falling within thescope of the appended claims.

What is claimed is:
 1. A loader slot bearing comprising: an annularhousing having a first axial housing-surface, a second axialhousing-surface and an interior area extending between the first axialhousing-surface and the second axial housing-surface, the interior areabeing defined by an inner bearing surface that extends between the firstaxial housing-surface and the second axial housing-surface, the innerbearing surface having a concave contour defining a surface area and acircumference measured proximate to the first axial housing-surface, asingle slot extending axially partway into the inner bearing surfacefrom the first axial housing-surface, the slot having a slot arc sectionarea extending axially inward from the first axial housing-surface, theslot arc section area having a first circumferential slot-end, a secondcircumferential slot-end, and a slot arc length Al measured between thefirst circumferential slot-end and the second circumferential slot-end;a ratio of the slot arc length Al to the circumference of the interiorarea being about 0.20 to about 0.35; and a truncated ball having aconvex spherical exterior surface extending between a first axialball-surface and a second axial ball-surface, the truncated ball beingpositioned in the slot and rotated so that the truncated ball isrotatably retained by the inner bearing surface, the truncated ballbeing angularly misalignable relative to the annular housing.
 2. Theloader slot bearing of claim 1, wherein the slot having a first lateralwidth W1 measured between the first circumferential slot-end and thesecond circumferential slot-end, and the truncated ball having a firstaxial width W2 measured between the first axial ball-surface and thesecond axial ball-surface, the first axial width W2 being less than thefirst lateral width Wl.
 3. The loader slot bearing of claim 1, whereinthe slot arc section area having a first radius R1, and the sphericalexterior surface having a first outer diameter D1, the first radius R1being greater than the first outer diameter D1 divided by
 2. 4. Theloader slot bearing of claim 1, wherein the inner bearing surface havinga first center of curvature C1, and the slot arc section area having asecond center of curvature C2, the second center of curvature C2 beingpositioned a distance D2 from the first center of curvature C1.
 5. Theloader slot bearing of claim 1, wherein the annular housing having asecond axial width W3 measured between the first axial housing-surfaceand the second axial housing-surface, and the slot having a first axialdepth D3 extending from the first axial housing-surface toward thesecond axial housing-surface, a ratio of the first axial depth D3 to thesecond axial width W3 being about 0.40 to about 0.60.
 6. The loader slotbearing of claim 1, wherein the inner bearing surface further comprisesa radial groove centrally located axially between the first axialhousing-surface and the second axial housing-surface and extendingcircumferentially around the interior area.
 7. The loader slot bearingof claim 1, wherein the slot further comprises a notch extendingradially outward into the annular housing, the notch having a firstradial depth D4.
 8. The loader slot bearing of claim 1, furthercomprising an insert positioned in the slot, the insert having an insertarc section area that conforms in shape to the slot arc section area. 9.The loader slot bearing of claim 1, wherein the truncated ball having acylindrical bore extending between the first axial ball-surface and thesecond axial ball-surface, the bore being defined by an interiorball-surface.
 10. The loader slot bearing of claim 1, wherein thetruncated ball is dropped into the interior area of the annular housing.11. The loader slot bearing of claim 1, further comprising a linermolded between the truncated ball and the annular housing.
 12. Theloader slot bearing of claim 11, wherein the liner is molded over aninsert positioned in the slot.
 13. The loader slot bearing of claim 11,wherein the liner is formed of an injection-moldable material.
 14. Theloader slot bearing of claim 1, further comprising an insert positionedin the slot and a liner molded between the truncated ball and theannular housing, wherein the liner has a first hardness and the inserthas a second hardness that is greater than the first hardness.
 15. Theloader slot bearing of claim 1, wherein the slot extendscircumferentially from the first circumferential slot-end to the secondcircumferential slot-end and the inner bearing surface extendscontinuously circumferentially a bearing surface arc length outside ofthe slot from the first circumferential slot-end to the secondcircumferential slot-end.
 16. The loader slot bearing of claim 15,wherein the bearing surface arc length is defined by a ratio of thebearing surface arc length to the circumference of the interior areaabout 0.65 to about 0.80, to provide support for the truncated ball. 17.The loader slot bearing of claim 1, wherein the concave contour iselliptical.
 18. A rod end comprising: a loader slot bearing comprising:an annular housing having a first axial housing-surface, a second axialhousing-surface and an interior area extending between the first axialhousing-surface and the second axial housing-surface, the interior areabeing defined by an inner bearing surface that extends between the firstaxial housing-surface and the second axial housing-surface, the innerbearing surface having a concave contour defining a surface area and acircumference measured proximate to the first axial housing-surface, asingle slot extending axially partway into the inner bearing surfacefrom the first axial housing-surface, the slot having a slot arc sectionarea extending axially inward from the first axial housing-surface, theslot arc section area having a first circumferential slot-end, a secondcircumferential slot-end, and a slot arc length A1 measured between thefirst circumferential slot-end and the second circumferential slot-end;a ratio of the slot arc length A1 to the circumference of the interiorarea being about 0.20 to about 0.35; and a truncated ball having aconvex spherical exterior surface extending between a first axialball-surface and a second axial ball-surface, the truncated ball beingpositioned in the slot and rotated so that the truncated ball isrotatably retained by the inner bearing surface, the truncated ballbeing angularly misalignable relative to the annular housing; and ashaft having a longitudinal axis, the shaft extending from and beingintegral with the annular housing; and the slot being centrally locatedalong the longitudinal axis.
 19. The rod end of claim 18, wherein theslot is located adjacent to the shaft.
 20. The rod end of claim 18, theinner bearing surface having a first center of curvature C1, and theslot arc section area having a second center of curvature C2, the secondcenter of curvature C2 being positioned a distance D2 from the firstcenter of curvature Cl , wherein the second center of curvature C2 islocated closer to the shaft than the first center of curvature C1. 21.The rod end of claim 18, further comprising an insert positioned in theslot and a liner molded between the truncated ball and the annularhousing, wherein the liner has a first hardness and the insert has asecond hardness that is greater than the first hardness.
 22. The loaderslot bearing of claim 18, wherein the concave contour is elliptical.